2006 GMC Yukon Owner's Manual - Page 178

Fog Lamps If your vehicle has fog lamps, use them for better vision in foggy or misty conditions. The fog lamp button is located on the left side of the instrument panel. Press the button to turn the fog lamps on. Press the button again to turn them off. An indicator light will glow in the button when the fog lamps are on. Remember, fog lamps alone will not give off as much light as your headlamps. Never use your fog lamps in the dark without turning on your headlamps. The fog lamps will go off whenever your high-beam headlamps come on. When the high beams go off, the fog lamps will come on again. The fog lamps will be cancelled after the ignition is turned off. If you still want to use the fog lamps after you restart the vehicle, you will need to press the fog lamp button again. Some localities have laws that require the headlamps to be on along with the fog lamps. Your parking lamps and/or low-beam headlamps must be on for your fog lamps to work. 3-18